1. Coastal Processes
Understanding coastal processes is important when trying to preserve and protect beaches
In Florida, 75% of the population (10.5 million) live within 10 miles of the coast

2. Waves are present along all coastlines, and are created by wind blowing over the ocean
Wave action is responsible for the presence of well-sorted, well-rounded sands along the beach. Waves are often the main agent of erosion
As waves approach the shoreline they grow in height and eventually break. The zone where they break is termed the surf zone

3. As a wave crest approaches an irregular coastline it bends
As a wave crest approaches an irregular coastline it bends. This is called wave refraction, which causes wave energies to be concentrated at headlands and dispersed at bays

4. Waves approaching a shoreline at an angle cause two important processes
Longshore Drift – the gradual lateral movement of sand along the beach
Longshore Current – a shallow-water current parallel to the shore

5. Tides are another process that occurs along every shoreline
Tides are the twice daily rise and fall of the sea, and are caused by the gravitational attraction of the Moon, and to a lesser degree the Sun

6. Coastal Setting and terminology

7. Beach Profile

8. Accretion or erosion of a beach is dependent on its sand budget
Accretion or erosion of a beach is dependent on its sand budget. There are several inputs and outputs of sand to a beach

9. Often see interesting erosional and depositional formations
When the total inputs equals the total outputs, the beach is said to be in equilibrium. If the beach is not in equilibrium either erosion or deposition will occur
Often see interesting erosional and depositional formations
Erosion of a cliff to form
a wave-cut terrace
Deposition of sand at Cape Cod
to form a spit

10. When sand outputs is greater that sand inputs beach erosion occurs
Humans have tried to slow beach erosion by stabilizing the beach. There are two types of stabilization techniques
Hard Stabilization – Emplacement of hard structures, including groins, jetties , and sea-walls, to protect the beach. Often involves significant construction and coastal engineering
Soft Stabilization – Replace lost (eroded) sand with new sand. New sand can either be sediment picked up from dredging, pumped from offshore, or from sand deposits on shore. Costs roughly $1 million/ mile

11. Two examples of the use of groins
Two examples of the use of groins. These structures trap sand that is being moved along by longshore drift, causing a build up of sand on one side and a depletion along the other. This is a dangerous practice and could lead to “New Jerseyization” of the shoreline

12. Sea-level rise is another problem facing coastal communities.
Global warming may lead to increased rates of sea-level rise.
Most models expect a rise of meters within 50 years